What Makes People Hoard: A HealthCentral Explainer

Patient Expert

According to a new study, people who suffer from hoarding disorder have an area of the brain that is underactive when they are trying to make decisions about the possessions of others, but overactive when they’re trying to make decisions about the things they own.

The study, published in the Archives of General Psychiatry and funded by the National Institute of Mental Health, found these reactions in the anterior cingulate cortex and insula--areas of the brain that govern such things as assessment of risk, error monitoring, emotional decisions, unpleasant feelings, and weighing the value of objects.  The finding may explain some of the key symptoms of hoarding disorder, including indecisiveness, inflated estimates of the value of objects, and emotional distress caused by the prospect of getting rid of possessions.

What the Study Found

Perhaps the most interesting aspect of the study, however, was that researchers compared the responses of people with hoarding disorder and people who suffered from obsessive compulsive disorder (OCD), a condition traditionally thought to encompass hoarding.  Both groups--as well as a control group of people who suffered from neither condition--were asked to bring in junk mail and old newspapers that belonged to them.  The brains of the participants were then scanned using MRI technology to watch for changes in the brain when they were asked to get rid of either their own mail or papers and similar pieces of mail or newspapers that did not belong to them.

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The MRI scans showed that the underactive and overactive responses of the anterior cingulate cortex and insula seen in people with hoarding disorder was not seen in the brains of people with OCD. In other words, while people with OCD responded about the same to getting rid of their possessions and those that did not belong to them, people with hoarding disorder seemed abnormally disinterested in the possessions that weren’t theirs and abnormally interested in their own things.  Predictably, people with hoarding disorder kept more of the valueless objects than either people with OCD or those in the control group, since they showed evidence of being more emotionally attached to the objects and were unable to make decisions about which to discard and which to keep.

What This Means

Because the brains of the two groups did not respond the same in the experiment, researchers say their findings may mean that hoarding is not actually a symptom of OCD, but rather a separate condition that may require different treatment.

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The finding is very timely, given that the American Psychiatric Association is currently preparing to publish the next version of the Diagnostic and Statistical Manual of Mental Disorders, or DSM-V, which is the “bible” for diagnosing and treating mental illness. Experts have already proposed that hoarding be listed as a separate condition from OCD in this new version of the DSM-V.

Sources:  Washington Post; ScienceBlog; Medical News Today